The methods and systems disclosed herein relate to an explicit control messaging protocol. More specifically, a low-cost and low-power explicit control signaling for Universal Serial Bus 2.0 (USB2) and similar protocols is disclosed.
In its present state, USB2 utilizes the Link Power Management (LPM) system to issue control messages. This system defines an implicit signaling mechanism for the host to issue a control message (such as Suspend or Reset) based on the duration of a link idle time, or a control transfer for entry to L1.